Abstract [en]

This study evaluated the possible uses for a custom-made Capillary Electrophoresis Contactless Conductivity Detector (CE-CCD). One of the key objectives was to determine whether measurements of conductivity with the device could replace UV-spectroscopy to analyze a range of samples, in particular PVA-MB and monosaccharides. Furthermore, to determine the feasibility of using the specific device as a substitute for UV-spectroscopy analysis, two commercial reference devices were used: one contact based conductivity detector and one potentiostat. Changes in resistance and voltage drops of samples containing the analytes were used to determine whether the analysis with the custom made CE-CCD could replace analysis with UV-spectroscopy.

The signal from the PVA-MB compared to variation in the signal of the background electrolyte was discovered to be too great for CE-CCD to be applied as a substitute for UV-spectroscopy. However both monosaccharides analyzed in the study, glucose and galactose could be detected. Glucose could accurately be detected down to 50 μM and galactose down to 25 μM. A semi-empirical calculation estimated a lower limit of 5 μM for glucose and roughly 8 μM for galactose.

PVA-MB could not be detected with the custom made CE-CCD while the monosaccharides can be detected in a range low enough to allow the detector to replace UV-spectroscopy for analysis. The best measurements taken with the detector were not as low as the best data found for UV-spectroscopy, but similar electrochemical applications were found to have reached similar or better values. Further development of the detector may lower its limit of detection to approach and possibly exceed the better measurements taken with UV-spectroscopy.